Japanese National Committee on Large Dams. Dams in Japan, No. 10

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The wall

has 2

or 3 hinges in the middle,

which serve to

prevent the

wall

from cracking.

The bedrock

has several faults crossing

the dam axis in the concrete

s€ction, and careful treatment was

required for the

foundation.

Some fractured

zolles

were replaced by special

keyblocks

with

big flanges on the top, which were

made of

reinforced concrete

and supported on sound

rock of the both

tides.

They will work to transmit the load

of the dam to the

foundation safely.

Another characteristic

is the block

joint

of the conqote

section,

which

was designed in sloping-joint

type. Each

joint

surface

was

decided to

parallel

to the direction of

the

principle

stress. It means the shearing

stress on the surface

would

be minimurn,

joint

grouting was not necessary.

Inspection

GollerY

Core

Filter

Tronsitlon

Rock

TYPICAL

CROSS

SECTION

GOCT

FILL

SECTION)

CONCRETE

CUTOFF

VALL

DETAIL

HINGE

JOINT

SKETCH

e,-aro

Znd

Hinge)

er-ecso(3th

Hlnge)

UPSTREAM

VIEW

F'UKADA

DAM

Location

Nearest

City

River

Purpose

Catchment

area

Mean

annual

discharge

Years

of construction

Type

Foundation

Height

Crest

length

Volume

Spillway

Type..................

.....

Uncontrolled

Typc and number

gate

......................

Maximum

discharge

capacity ................. l2nrlls

Reservoir

Gross capacity

..........

8.7

10hr

Effective capacity

...... 8.0x

10tnl

Area ..................

..... 0.50Km'

Drawdown range

..................,,...,......... /7m

Owner

.,..............

.........., Ministry

of Agriculture, Forestry and Fisheries

Engineering

............... Ditto

Construction

by J. V. of Obayashi-Gumi

Co., Ltd. and Hazama-Gumi

Co., Ltd.

The

history of the irrigation ir this area dates back to 1882, when a big diversion scheme ftom

lake

Inawashiroko

(one

of the

largest lakes

in Japan) was implemented for

land reclamation, and this established

the base of this district's

prospenty.

Afterwards

several improvements were carried out

for the irigation system, but additional water resources develop-

ment

became necessary

due to recent reformation

of agricultural structure.

The Fukada

dam is the biggest structure of this

project and the reservoir is used for regulation

the natural runoff

from

the lake

for the efficient use of water.

The bedrock

consists of alternate layers of tuff

sandstone and

mudstone, and the weathering

of those rocks reaches

deep

into the

ground

that rock material is not available near the site.

Furthermore, the valley

is overlain thickly by

dver

"a- \.

Koriyama-shi, Fukushima-ken

Koriyama-shi

Irrigation

1.3Km'

r97r-1979

Zoned earth

dam

Tuff mudstone

and

sandstone

55m

340m

1.,1,79,000m,

PLAN

deposit.

Under

such a

geological

condition,

no other

dams

can

applied

exc€Pt

for the

zoned- earth

dam'

The

imper-

vious zone

was filled

with clayey

"",th

th"t

"o-",

ftom

the

weathered

rock, and

the

material

of other

Part

was river

de-

posit

and

from several

borrolv

areas

which

were selected

paying

attention

theif

mechanical

strength'

small

quantity of

rock rnaterial

which

was ca[ied

long

n'ay

was used

for slope

protection

against

erosion

and scoring'

The river deposit

is very

loose

ani

weat

in bearing

capacity,

the

excavation

was

made to

reveal

the

bedrock.

As the Fukada

dam

*oufA

t"1"tiu"fy

f,ilft

toilt-tuitiout

iock

zone,

the

dam

was designed

after much

investigation

earthquake

resistance.

when

the

rr,riy"g;rii-uq"ake

June.,

1978 struck

this

disftict

with

magnitude

7.4,

the

dam

withstood against

it, and

time

histoi[i

of a""eleration

were

recorded

by strong

motion

seismogaphs

installed

at the

qrest

and

foundation of

the dam.

Basedontheserecords,thedynamicresponseanalysiswasmadebythefiniteelementmethod'ThecompaTisonof

time

histodes of

acc€leration

outar'neo

t om the

analysis

with

observed

iecords

led

to the

conclusion

that

the

seismic

be-

havior

had been in

elastic

,"rponr".--

fi'n*ir

ttrat

siiding

faiture

did

not happen

even

inside of

the dam

during

the

ea h-

quake.

The

experience

successful

construction

would

zoned

earth

dam.

serve

enhance

earthquake-proof

design

technique

such

high

.rqo

t-l

zon" I

zonc lt

zonc fr

oroinoge

toyer

corloin

grout

Fittcr

Bulk

rockfill

originst

ground

t-!-L

fs.L

l!8

x*.L !f8

TYPICAL

CROSS

SECTION

gHw'

!34 6

gFwL

!ra.o

Og ag

',[i

ir-

PROFILE

ALONG

DAM

AXIS

roon

HATANAGI-No.

Location

Nearest

City

River

Purpose

Catchment

area

Mean

annual discharge

Years

of construction .

Type

Foundation

Height

Crest length

Volume

Spillway

Type

and number of

gate

Maximum discharge capacity

Reservoir

Gross capacity

Effective

capacity

Area

Drawdown range

Owner

Engineering

Construction

Tashiro, Sizuoka-shi,

Sizuoka-ken

Sizuoka-shi

Ohi River

Hydroelectric

318.0Km'

22.95m'ls

t957-1962

Hollow

gravity

Slate

and Sandstone

125m

292m

597,500m'

Controlled

Crest

radial

gateX4

2,lrffim3ls

I07.4X

101n3

80X

106m3

2.5Km'

The Chubu

Electric

Power Co.,Inc.

Ditto

Hazama-Gumi,

Ltd.

PLAN

TYPICAL CROSS

SECTION

ABUTMENT

UPSTREAM

VIEW

The Hatanagi-No.

1 dam, 125m high, is the

highest hollow

gravity

dam in Japan. It was

also the

highest

one

in the

world

at the

time of its construction

(1961).

was constructed on the River Ohi as the

upper resewoir of the llatanagi

No.

power plant

with an installed capacity of 137MW.

The lower dam

(the

Hatanagi No. 2 dam)

is also a hollow

gavity

dam with

a height

of 69m.

This

plant

is a mixed type

pumped

storage station utilizing

both the natural river flow and the

pumped-up

reservoir water.

The upper

reaches of the Ohi River, where the Hatanagi

No. 1 dam is located in the Akaishi formation,

being

held be-

tween the

fossa magna on tlle east and the medium tectonic

line on the nest.

The foundation

rock of the dam site is mainly

composed of slato laminated

with

hard sandstone in some

places.

The unit

block shapes of the

hollow

gravity

dam are

generally

classified

into four

types

(i.

e. T-tlpe, I-type, U-type

and

ll-type) by

their horizontal

cross

section.

As for

the Hatanagi No. 1 dam, the ll-type

section was adopted

for the blocks

in the riverbed

part,

so as

to keep

enough spac€

for

penstocks

and diversion facilities,

and also

be stable

against

the extemal force acting in the

direction

parallel

with the dam

axis.

However,

the I-type section

was

adopted for

the other dam blocks located

both left and right river banks

in order

to avoid

undesirable structural effect

possibly

induced by

impairing the vertical

qoss-sectional

symmetry of the II-t]?e sec-

tion's

basement, on

account

of being

placed

on the foundation

rock with steep slope.

case of both I-type and ll-type section, all

the longitudinal block

joints

the downstream surface of

the dam were

tightly

closed in the

same

way a6 those on th€ upstream,

in order to increase the aseismatic stability of each dam block

and

also

to decrease

the thermal

gradient

oc{uring in so-called

diamond hcad

portion, perpendicularly

to the dam-axis,

taking

the large annual

temperature

difference in tlle region

into consideration.

From

economical design

point

view, the

power

house building was constructed at the foot of the

dam, using the

space

qeated

between the

downstream surface of the

dam and the spillway

apron, and the reservoir water from the dam

crest is flowing

over the

power

house roof

which forms a

part

of the apron.

Such a way

of desigt

may

said most economical

for a

power house being constructed in a narrow valley.

In this

case, the

width

the overflow section of the

dam is designed as wide as that of the river, in order

to decrease

the intensity

working load on the roof and an adverse

influence

on it due to

possible

hydraulic vibration caused by

over-

flowing water.

As to the

longitudinal cross sectioo

of the

power

house

roof, a

parabolic

surface line was adopted consider-

ing

hydraulic smoothness.

The

roof of the

power

house

structually

composed

of steel and

reinforced concrete as composite

girder

with

thick-

ness

of 50cm.

Concerning with

the

cross-sectional shape of the

dam cr€st, a

parablic

surface line with large curvatur€ extensively

over-hanging

upstream

was

also

adopted in order

not to cause excessive

tubulent flow mixed with air along the

spillway

channel and

consequently to

distribute the over-flowing

water load uniformly

on the

power

house roof.

In this case,

however

a discharge coefficient

value for

the dam spillway may

get

rather low.

In general,

the hollow

gravity dam has

an advatrtage

of receiving less amount of uplift

pressure

acting on its bottom

comparison

with that of conventional

gravity

dam,

because the

foundation rock in hollow

ponion

is left uncovered

vdth

dam

conqete.

However,

in case of the

Hatanagi No. 1 dam,

all the foundation

rock was covered

with the dam

base

conqete,

in ordet

provide

a sufficient shearing resistance

force for

dam stability.

IV ERSION

order

to fulfill these

two conflicting requirements, i. e., the less up-lift

pressure

and

the more

shearing resistance

force,

a large

number of

drain holes

were

drilled, within the hollow

portioo

concentratedly,

on the

base concrete

mat adja-

cent to

the downstream

side of the diamond

head, and the total

number of the drain

holes drilled

on the

whole

basement

area amounted

1,380.

As mentioned

above,

the foundation rock of the dam site mainly consists of slate laminated with

hard

sandstone in

some

places.

And, the

massive rock itself

hard

enough as the basement

for the dam, although

toints

and

cracks are fairly

pre-

dominant.

However

there were

two fault zones on the dam foundation area, one being lm wide and

the other

;

no technical

problem

on foundation

treatment was lefi to be solved further, after the dental work having

been accomplished

on them.

executions

of the curtain

grouting

work, the

grout

holes, spaced 1.5m center to center,

were dritled

in one or two

lines parallel

to the dam

axis, at the upstream hcel of the diamond

head

by adopting

the

stage

grouting

method,

with

the

maximum

drilled

depth of 50m, and the maximum allowable

grouting pressure

o144kdcm'z-

to the consolidation grouting work

executed over the

whole dam

foundation

area,

the

grout

holes,

spaced 5m apart

in both

directions

being

parallel

and

perpendicular

to the dam axis were drilled to a depth of 12m, and

the c€ment slurry

was

grouted

with

the maximum

grouting

pressure

of l2kglcmr

by the stage

grouting

method.

On the upstream

cofferdam site, the riverbed is overlaid by a

gravel

deposit of about 20m deep.

Therefore, the

ICOS method $,as adopted in order to construct a cut-off x,all for

the

lilst time in Japan,

and

was

suc-

cessful in

stopping

seepage ftom the riverbed.

The

thickness

of the cut-off $'all was 0.6m and the total execution area of

that work was

1,400m'.

The

available

drawdown of the Hatanagi No. I dam is 44m and

its

static

and

pumping-up

heads fluctuate widely ftom

51m to 102.7m

depending upon

the

operational mnditions.

This wide

range of fluctuation in reservoir head was considered

to impose a fairly severe working

effect on the

pump-

turbine operation.

Therefore,

such a remarkably large-scale reversible

pump-turbine never manufactured by that

time

(1961)

in Japan was

concluded

to be adopted

after detailed

technical

studies.

In the

southem Japan Alps, from where tlle River Ohi dses, there

are many mountains of 2,000

to 3,000m in altitude.

The topographic

configuration of that area is

very

steep,

and the valley is very deep.

On the upstream

region of the Hatanagi No. 1 dam, there are

many land-slide spots and degraded zones.

Due to

these

geological

features, the volume of sediment iDflow

into the Hatanagi No. 1 reservoir is very

large

in com-

parison

with

that in other regions.

In these twenty

years

after completion of the Hatanagi

No. 1 dam, the total volume of ttle sedimentation is about 25.4

1Om!,

and accounts for about 24

percent

of the total storage

capacity.

On the downstream

of the Hataragi No.

1 dam, there are

many dams such as the Hatanagi

No. 2, the Ikawa,

and

othe$

constructed in

cascade.

These

dams are

operated by a centralized

remote-control

system using computer technology.

KAJIKAI4{A

DAM

Location

Nearest

City .

River

Purpose

Catchment

area

Mean

annual

discharge

Years

of construction

Type

Foundation

Height

Crest

length

Volume

Spillway

Type

and

number

gate .

Maximum

discharge

capacity

Reservoir

Gross

capacity

Effective

capacity

Area

Drawdown

range

Owner

Engineering

Construction

Shibata-shi,

Niigata-ken

Niigata-shi

Kaji

Flood control

88km2/s

13.2m3

1967-r974

Gravity

Granodiorite

107m

286m

428.000m'

Controlled

Crest

radial

gate

and Conduit radial gateXZ

1,600m3/s

22.5X

106m3

18.0X 10'm3

0.6km'z

42.6m

Niigata-ken

Ditto

J.V.

of Kumagai-Gumi

Co., Ltd.,

Sato Kogyo

Co., Ltd. and Taisei Corp.

Kajikawa

Dam is a consete

gravity

structure with

two dewatedng conduits for flood control

and one

crest radial

gat€

spillway.

The

foundation of the dam is

ganodioritic

rocks in Mesozoic,

intruded by rhyolitic dykes.

The base rock is

generally

massive,

and

partially

shows

hydro-thermal

alteration

by the dykes. There

were

only a few faults which might affect

adversely

to dam stability. But the faults running horizontally

were recognized along the both banl$ of the stream, dip-

ping

toward

right bank. Especially, as the safety factors

on the left bank

were not

large enough to withstand dam sliding,

the faults

around the toe of the dam was replaced

vr'ith

concrete

part.

PLAN

TYPICAL

CROSS

SECTION

-285.50

___

UPSTREAM

VIEW

10.

KAMISHIIBA

DAM

Location

Nearest

City

River

Purpose

Catchment

area

Mean

annual

discharge

Years

of construction

Typ"

Foundation

Height

Crest length

Volume

Spillway

Type

and number

gate

Maximum

discharge

capacity

Reservoir

Gross

capacity

Effective

capacity

Area

Drawdown

range

Owner

Engineering

Construction

Shiiba-son,

Higashiusuki-gun, Miyazaki-ken

Hyuga-shi

Mimi

River

Hydroelectric

2LI.Okm'

27.07m31s

1952-1955

Arch

Graywacke,

slate

110.0m

341.0m

350,000m3

Controlled

spillway

(ski-jump

type)

Crest radial

gateX4

1,800m'/s

97.56X

106m',

76X 106m3

2.66km'

45.0m

The Kyushu

Electric Power Co.,

Inc.

Ditto

Kajima

Corporation

Kamishiiba

Dam is situated on the upper reaches of

the Mimi River which flows through

the central

part

Kyushu

Island. This

river, having 900kmi catchment area, flows into

the Pacific Ocran. This area is

mountainous

with ranges up

to 1,500

meters in elevation cut by deep, steep

valley

and

annual rainfall averages approximately 2,500mm.

This dam,

110 meters

high and containing 350,fi)0 cubic

meters of conqete, is the

first large arch dam canstructed

Japan.

The

Kamishiiba

power

station is capable of

generating

90,m0KW

power

at maximum,

and annual energy

production

of the

power

station including those of the dolvnstream

power

stations was expected to

273,000MWh

at initial

planning

stage.

Various

studies on the

design

and methods of

constructiotr of the

dam were made, however,

it was

finally

decided

introduce

latest technique ftom abroad through the

aid of Overseas Consultants Incorporated

(O.

C. I.).

The dam

site shows a

V-shaped topogaphy with the

ratio of valley at dam crest to dam height approximately 2.5

which provides

favorable condition

for

arch dam

construction. The

geology

of the dam site is

mainly

gralwacke

and slatc,

with

intercalation

of altered

rock

and

graphite.

Graywacke

and

slate

are rigid except the

part

several

meters deep ftom

the surface,

however since slate is dch in schistosity

and

phyllitic,

the compressive and elastic strength of the slate

is less

than that

graywacke.

There

was found a east-west trending fault, dips

45 to 50"N, 1.8 metels

wide,

consisting of

graphite

rear

EL 470

meters on

the left abutment and determination of

the dam location and

height was influenced

by this fault.

order to

prevent

the arch thrust

applyrngs, directly this zonc

thrust block was

provided.

And also,

as the Ieft abut-

ment was

located at downstream side as far as

practicable

to avoid the slate

bed on the

upper

left

bank, the arch

is twisted

a little

against the downstream direction.

Kamiishiba

dam is an arch

dam of a constant central

angle with radius of 142.398 meters and a central angle

1L4'52'34"

at dam crest

(EL

483m).

The maximum

thickness of the dam body is 27.7

meters at the

bottom

(EL

373m) and the minimum thickness

is 7 mete$

the dam crest.

Complete stress analysis by

the trial load method

with horizontal arch and vertical cantilever

was made.

In these

studies, modulus o{ elasticity of conuete,

210,000kg/cm', that

of th€ foundation rock, 70,000kg/cm', and

allowable

shearing

stress of the foundation rock, 35kg/cm'was

used based on experiments.